Studying how severe weather affects birds

How documenting storm impacts on birds can advance our understanding of hurricanes and other weather events By Jeremy D. Ross | Published: 2/22/2018

This Barbuda Warbler was spotted on the island of Barbuda in mid-October 2017. Before Hurricane Irma engulfed the tiny island with 185 mph winds in early September, the warbler, Barbuda’s only endemic bird, numbered between 1,000 and 2,500. Photo by Frantz Delcroix

An unfamiliar silence pervades the morning light. Stings of ozone eddy among the fresh scent of damaged vegetation. A world upside down is carpeted in green leaves. Gnarled limbs continue their skyward protest of yesterday’s tempest. This is your go-to birding spot and a place you’ve visited many times before, but now you’re looking at it as through a shattered mirror. The scale of the calamity seems far removed from the neatly colored maps dissected during the evening weather reports.

“How could birds survive through such destruction?” a shrunken voice asks. On cue, the emerging light reveals its answers: wet mounds of tattered feathers line the winding piles of debris; a miserable sentinel hangs one wing low, motionless in the shadows; scattered nests lie stretched and battered, though still tragically recognizable in form. Standing witness to this natural disaster, one may doubt whether anything can be done to help. Yet in these moments, documenting such observations can contribute to the study of weather impacts, potentially reducing threats from future and more extreme events.

This article was originally published in the January/February 2018 issue of BirdWatching magazine. Subscribe

Severe weather outbreaks, known in scientific literature as a version of extreme climatic events, are fundamentally complex phenomena that often evade scientific study. As with human-caused disasters (e.g., oil spills), they are generally assessed after the fact, can suffer from site-access restrictions, and are confounded by debris. From a basic scientific perspective, post-storm studies also contend with a lack of replicability and randomization that steal power from traditional statistical analyses.

Yet we understand from anecdotal reports and single-event case studies that severe weather can have profound impacts on birds. For example, two successive hailstorms in 1954 killed perhaps 64,000 or more waterfowl in Alberta. Likewise, a tornado in Iowa in 1940 resulted in thousands of bird deaths in one town. Afterward, the density of remaining birds was only 4 percent that of a nearby, unaffected town. And beyond reports of death, evolution itself has been driven by an extreme climatic event: Following a severe six-day cold snap in 1996, Cliff Swallows of western Nebraska underwent a significant shift toward larger body size. All told, however, we still have only a cursory understanding of the impacts of severe weather events on birds despite the clear implications they may have for species conservation.

A common misconception is that nature is eternally resilient, having evolved under various regimes of severe weather outbreaks for millions of years. It is true that species can recover from extremely destructive events, such as volcano explosions. Yet only through the grace of recolonization can they be resurrected. Species that have suffered a thousand insults by way of habitat fragmentation, environmental degradation, and overharvest may not have the capacity to re-establish themselves to ranges lost during extreme climatic events.

Recall the scene presented at the outset of this article; if this was the last remaining pocket of breeding or wintering habitat for a bird, then it would be extremely imperative to understand how the species was immediately affected, how long it will take its critical habitat to recover, and whether we need to invoke drastic conservation actions to ensure that the echoes of secondary extinction risk do not reach this bird. The last point is particularly sinister, as the fortunate few that survive the initial event might later succumb to a lack of critical food and shelter resources.

Threats of secondary extinction are playing out right now on the hurricane-raked island of Barbuda, where the endemic Barbuda Warbler clings to existence in Hurricane Irma’s wake. Reports of survivors during post-storm assessments by the Antigua-based Environmental Awareness Group offer a glimmer of hope. However, secondary threats such as lasting woody vegetation damage, saltwater intrusion, and the proliferation of feral animals starving in the absence of human care may all conspire to push the warbler further toward extinction. We all want to help, but with limited knowledge of how such species and their habitats rebound, conservation is forced through a maze of blind corners.

Migratory birds may be disproportionately impacted by the anticipated shifts in severe weather patterns. For instance, populations arriving earlier to northerly breeding grounds in response to earlier spring thaws can be devastated by intense spring snowstorms. This has been documented among colonies of American White Pelican in North Dakota, where a 16-day advance in arrival date since 1965 more than doubled the resulting hatchlings’ exposure to deadly cold snaps and snowstorms. Furthermore, severe thunderstorms in the central “tornado alley” are expected to shift northward and eastward into the Upper Midwest and Great Lakes region. Such a geographic shift could imperil entire bird communities that have not evolved under such a weather regime, which threatens devastation for the renowned songbird migrations of the region.

Holding off extinction

The limits of species resilience are often reached during the most extreme of weather events. When entire populations succumb, we label these “local extinctions.” If the last remaining populations are too reduced, fragmented, or otherwise degraded, then severe weather can translate into outright species extinctions. We know that transient weather events such as drought or cold snaps can determine where species or even entire biological communities exist, depending upon the severity, frequency, and spread of such perturbations. Therefore, it is contingent upon those tasked with preventing human-caused extinctions that they best understand and discern natural “background” extinctions from those that are linked to human disruptions. Only with such knowledge can we optimally account for natural resilience within a species as well as determine whether it may require rapid and targeted management during post-storm recoveries.

Severe weather can influence the evolution of birds. After a deep freeze in 1996, Cliff Swallows in Nebraska shifted toward a noticeably larger body size. Photo by vagabond/Shutterstock

A number of conservation groups have developed the capacity to rapidly assess resiliency and recovery of particular endangered birds following a disaster. In the aftermath of 2017’s catastrophic hurricanes, such efforts could provide the means to stave off extinction for a few species found only on the hardest hit islands.

BirdsCaribbean has been coordinating efforts since Hurricanes Irma and Maria to assess the storms’ immediate and lasting impacts on bird populations. It is leveraging an established network across the Greater and Lesser Antilles to use local experts to gather data about the occurrence and abundance of threatened and rare species, such as the aforementioned Barbuda Warbler and Dominica’s “Sisserou” or Imperial Amazon. This network of researchers also possesses a collective ability to study avian impacts across a gradient of destruction, ranging from completely defoliated islands to those entirely unaffected. BirdsCaribbean has also worked with island collaborators to establish or continue existing monitoring efforts across the islands as a basis to quantify storm impacts. Such coordination across multiple island nations helps spread the information regarding how the storms affected bird communities. This is a first step toward formulating guidance documents for habitat restoration and management aimed at reducing hurricane threats for birds.

As the damage from a record-breaking hurricane season continues to reverberate, bird species found nowhere else face a long and uncertain recovery. BirdsCaribbean has established a crowdfunding drive specific to supporting both a series of surveys through critical bird habitats affected by the hurricanes as well as direct recovery actions to help bird populations. Without even stepping foot into the destruction zone, you can directly contribute your help in the form of donations. (See box below.)

Getting involved

If you who want to get your boots on the ground and contribute directly to our understanding of severe weather ecology, I invite you to enter the realm of citizen science. In your hands (or pockets, field bags, or purses), you likely possess the most powerful tools of a citizen scientist: a digital camera and smartphone. This technology is widely recognized for driving the ongoing growth of birding, particularly by easing the newcomer’s intimidation at identifying species and documenting possible rarities. The digital technology literally at our fingertips can overcome our collective feelings of inadequacy and despair when doubting what can be done to study or even counteract severe weather impacts on birds. What matters in this respect is that you have the ability to gather a high-resolution photographic voucher of the damage you are witnessing and that you can then share, notate, and catalogue the contents of the photos into an online database.

As part of the most informed, connected, and concerned collection of humans that have ever lived, you should not take for granted the infrastructure and technology at your disposal. Early naturalists had far less but still contributed much of our understanding of the natural world. A vast and expanding network of citizen scientists now represents our best bet to gain the necessary survey coverage to address the ecological complexities and global impacts of severe weather.

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Reservedly, you may ask, “But how can my untrained eye gather proper scientific data?” To this I respond that field science is at its core a collection of observations. Yes, small teams of biologists have traditionally gathered such data. However, as long as field observations are accompanied by information about the settings and conditions of their gathering, people with a wide range of skills and experience can collect them. With proper recording of “metadata” — location, time, walking direction, equipment used, weather conditions, etc. — a mishmash of anecdotes across space and time can become a data pile from which scientists can account for observer expertise while mining information.

Similar work forms the long-standing basis of the Christmas Bird Count and has produced a plethora of analysis products from eBird reports. Perhaps the most approachable citizen-science venue is iNaturalist, an online global community of amateur and professional naturalists who share and identify observations of any species they choose. Given the photo-centric and expert-curated framework of iNaturalist, it is also an ideal portal through which the birding community can share post-storm observations of avian impacts.

My research team at the University of Oklahoma has formed a public project within iNaturalist for the reporting of post-disaster impacts (or lack thereof) for any species. It can be freely accessed on the iNaturalist website or within the iNaturalist app under “Post-disaster assessments.” As the title implies, the project broadly concerns both natural and man-made disasters, and we accept citizen scientist observations for any species from across the globe. Anyone can join the project, contribute data to the central repository, and suggest the species identifications of storm casualties or survivors.

Generally, the data are recent photographs from the field, but they can include audio recordings of singing species or scanned photos from many years past. The primary stipulations are that the data can be plotted on a map to the nearest half-mile and that they are dated to the nearest half-day. Of course, the more details that can be provided about how, when, and where the observations were made, the more weight they will hold in any analysis. Again, reporting any observations can help to fill our scientific knowledge gaps concerning the ecological impacts of severe weather, so please dig up those old photos and notes!

Resilience

Anyone who witnesses the raw fury of natural disasters can feel helpless. It’s natural that we empathize with persons affected. Yet damage to plant and animal communities can also have lasting impacts on the human psyche, especially with greater personal attachment to nature. As a birder, you have an inherent reverence for the beauty and grace of birds. This connection likely translates to concern for birds’ welfare during hazards such as hurricanes, wildfires, ice storms, and heat waves. You also represent a capable frontline in the effort to better understand the ecology of such events.

Your personal knowledge of local habitats and bird distributions, ability to quickly access affected areas, and involvement with existing networks of bird-focused community groups has positioned you as an ideal contributor to the broader scientific study of severe weather. You can also directly support concerted survey efforts by other organizations or, perhaps of greatest impact, educate others about how severe weather impacts birds and how they can contribute their own observations to advance that science. The sooner we grow the network of informed citizen-science observers, the sooner we can arrive at effective means to enhance the resilience and recovery of birds and their habitats.

Jeremy D. Ross is an assistant professor in the Oklahoma Biological Survey at the University of Oklahoma. He studies severe weather ecology, and he’s part of an aeroecology working group, which is an interdisciplinary team focused on ecological processes that occur in the atmosphere. Previously he served as the executive director of the George Miksch Sutton Avian Research Center. You can find his lab at http://severeweather ecology.oucreate.com.

Worthy causes

Here are bird-conservation organizations that need financial help after the 2017 hurricanes:

On the front lines with iNaturalist

To contribute citizen-science data about the impacts of storms on natural areas, join the iNaturalist Network, which is part of the California Academy of Sciences. You can upload observations directly via your computer at www.inaturalist.org/projects/post-disaster-assessments. Or download the iNaturalist app for iOS or Android devices. In the app, tap “More” and then “Projects.” In the search field, type “post-disaster assessments” to find the project described in this article. Then tap “join,” and you’re ready to participate.